The color of the plug is not that relevant unless you are doing proper plug chops for WOT.
Anyway, for the E series bikes (89-94) Keihin CGK or DGK is the way to go. The CGK offers a nice snap up top. The DGK is smooth all the way through. DGK may seem boring at first, but on a long trail ride it really helps you keep the bike under control and keeps you from getting worn out. Either one will give you better throttle response than the stock needle.
I would get both, and try both. If your jetting is lean now, it will be close with the CGK/DGK. They are quite a bit richer than the stock needle. You'll probably end up dropping that pilot down to 42/45 though. 150 sounds about right on the main for those needles, but yes, it could be a bit lean on the stock needle.